# Airspeed Sensors
Airspeed sensors are highly recommended for fixed-wing and VTOL frames. They are so important because the autopilot does not have other means to detect stall. For fixed-wing flight it is the airspeed that guarantees lift not ground speed!
# Hardware Options
Recommended digital airspeed sensors include:
- Based on Pitot tube (opens new window)
- MEAS Spec series (e.g. MS4525DO (opens new window), MS5525 (opens new window))
- EagleTree Airspeed MicroSensor V3 (opens new window) (eagletreesystems)
- Sensirion SDP3X Differential Pressure Sensor
- Holybro Digital Air Speed Sensor (opens new window)
- Based on Venturi effect (opens new window)
- TFSLOT Venturi effect airspeed sensor.
All the above sensors are connected via the I2C bus/port.
Additionally, the Avionics Anonymous Air Data Computer (opens new window) can be connected to the UAVCAN bus to determine not only high-accuracy airspeed, but also true static pressure and air temperature via onboard barometer and an OAT probe.
# Enable Airspeed Sensors
Unlike most other sensor drivers, the airspeed sensor drivers are not automatically started.
Enable each type using its corresponding parameter:
- Sensirion SDP3X (SENS_EN_SDP3X)
- TE MS4525 (SENS_EN_MS4525DO)
- TE MS5525 (SENS_EN_MS5525DS)
- Eagle Tree airspeed sensor (SENS_EN_ETSASPD)
Airspeed calibration information can be found in: Basic Configuration > Airspeed.
# Developer Information
- Airspeed drivers (opens new window) (source code)